Heretofore, a unit cell of a solid polymer type fuel cell is constituted of a membrane electrode assembly (MEA) including an electrolytic film and a pair of electrodes between which the electrolytic film is sandwiched, and a pair of separators between which the MEA is sandwiched (e.g., see Japanese Patent Application Laid-Open No. 2002-367631). Each separator of the unit cell is provided with supply manifolds and discharge manifolds of oxidizing gas and fuel gas. In an oxidizing gas passage of one separator, the oxidizing gas flows from the supply manifold to the discharge manifold. In a fuel gas passage of the other separator, the fuel gas flows from the supply manifold to the discharge manifold.
A portion between the pair of separators and a portion between the separator and the electrolytic film are sealed with a liquid gasket (an adhesive agent) provided along the outer periphery of the unit cell. In each separator, accumulation sections are formed in both the inner peripheral portion and the outer peripheral portion of a seal face with which is provided with the adhesive agent. The accumulation sections prevent the adhesive agent from protruding into the manifolds or out of the unit cell and the like during a manufacturing process of the unit cell.